北极光的知识(英文版).doc

Section A Finland Northern Lights
The Northern Lights, also known as “Aurora Borealis(北极光)” or the “Dawn of the North”, never fail to take your breath away. The aurora borealis is one of the most sublime(超群的) and magnificent natural phenomena on Earth. Before scientists cracked(侦破) the mystery of the auroras, men were drawn(吸引) and fascinated(强烈地吸引住) by these dancing and magical lights that were often found in mythology(神话) and legends. In Roman Mythology, it is said that the Aurora is the deity(神) of the dawn. In North America, the Inuits (爱斯基摩人)have many legends that explain them as spirits of the dead. They believed that the lights are the essences(精华) of deer, salmon(鲑鱼), seals and other animals that they hunted. Aristotle (亚里斯多德)thought it was glowing air gushing(喷出) from cracks in the sky. The appearance of the red aurora in medieval(中世纪的) times was feared as a bad omen (前兆) or a sign of God's anger. They believed the manifestation (显现)of the aurora indicated famine or war. Charles Hall (查尔斯·霍尔), a 19th-century polar explorer, exclaimed: "Who but God can conceive(想出) such infinite(无穷的) scenes of glory?" Oddly enough, the Maori (毛利人)thought that the displays were just reflections of a campfire(营火) or torches.
Regardless whether you believe the scientific facts or the legends behind its existence, you’ll still be captivated(吸住) by these supernatural display of lights, and there are countless destinations where you can see the majestic phenomenon. Finland（芬兰）, for example, should be a representative. Many visitors to Finland come with hopes of seeing the Finland Northern Lights. The best place to see the Northern Lights in Finland is in the northern Lapland region(拉普兰地区), which is almost entirely located within the realm(区域) of the Arctic Circle (北极圈). During the dark winter months here, when the sun rarely peaks(使达到最高峰) its head over the horizon, you can expect to see the Finland Northern Lights with regularity, and other peak(峰值) seasons include February through March and September through October. The time between 6 p.m. and 1 a.m. is the most intense period of the day. The highest probability within this timespan（时间间隔）to see the Finland Northern Lights is between 9 p.m. and 11:30 p.m., though they are certainly not restricted to this time frame. If you have never seen the Northern Lights wherever they commonly occur in the world, then you will be amazed the first time when you lay eyes on them.
The Northern Lights are similar to a sunset in the sky at night, but appear occasionally in arcs（弧光）or spirals（螺旋形物）usually following the earth's magnetic（磁性的）field. They are most often light green in color but often have a hint of pink. Swirling(涡旋形的) shades of blue, green, and pink are most common when it comes to the Finland Northern Lights. Strong eruptions also have violet(紫罗兰色的) and white colours. Red northern lights are rare, but can sometimes be observed on lower latitudes(纬度).
The Finland Aurora Borealis, while best seen in Lapland can also be witnessed as far south as the capital city of Helsinki(赫尔辛基) from time to time, though on average, there are only some twenty days out of the year when viewing them is possible in most southern parts of the country. Part of the reason why it can be difficult to see the Northern Lights of Finland in Helsinki is because of the fact that it is hard to escape to dimly lit areas. The relative lack of city lights is just one of the reasons why the Lapland region sees some 200 nightly occurrences every year, and one must also consider the region’s northern location. The lower reaches(区域) of the Arctic Circle are ideal for viewing the Northern Lights across the planet, which is why Canada and Alaska are good destinations in the Western Hemisphere(半球).
For those who are wondering what causes the Northern Lights in Finland, solar flares(耀斑) are largely responsible. These flares effectively cause solar winds and solar storms, which create lingering(游移的) atmospheric particles or matter. The Aurora Borealis is just caused by these charged(带电的) particles(粒子) ejected(喷出) from the sun. When these particles reach the earth, they collide(碰撞) with gas atoms in the earth's atmosphere causing them to energise( 释放出能量) which results in a spectacular multi-coloured light show. As such(因此), scientists can often accurately predict when the best times are for viewing the Northern Lights in Finland by keeping an eye out for(留心) solar flares. ( 757 words)
New Words
aurora [ɔ:'rɔ:rə] n. 曙光[C]; 极光[C];【罗神】(大写)奥罗拉(即曙光女神)
sublime [sə'blaɪm] a. 雄伟的；卓越的；壮丽的；超群的
crack [kræk] v. 敲破; 破(案); 破解
draw v. 吸引(注意等)
fascinate v. 强烈地吸引住
mythology [mi'θɔlədʒi] n. 神话
deity ['di:iti] n. 神
essence ['esns] n. 精髓，精华
salmon ['sæmən] n. 鲑，大麻哈鱼
gush [gʌʃ] v. 涌出，喷出
medieval [medi'i:vəl] a. 中世纪的，中古（时代）的;原始的
omen ['əumən] n. 前兆，预兆，兆头
manifestation [,mænifes'teiʃən] n. 显现
conceive [kən'si:v] v. 想像；想出
infinite ['infinit] a. 无穷的，广大无边的
campfire ['kæmp,faiə] n. 营火,篝火
captivate ['kæptiveit] v. 吸住；迷惑住
realm [relm] n.区域，范围
peak vt. 使达到最高峰 n. 最大量；巅值，峰值
timespan n. 时间间隔
arc [ɑ:k] n. 弧；弧光
spiral ['spairəl] n. 螺旋形物
magnetic [mæg'netik] a. 磁(性)的
swirling [swə:l] v. (使)打旋; 盘绕
violet ['vaiəlit] a. 紫罗兰色的
latitude ['lætitju:d] n. 纬度
reach n. 区域，领域，范围
hemisphere ['hemisfiə] n. 半球
flare [flɛə] n. (太阳的)耀斑，色球爆发
lingering ['liŋgəriŋ] a. 逗留不去的；游移的
charge v. 充(电)
particle ['pɑ:tikl] n. 颗粒，微粒；粒子
eject [i'dʒekt] v. 喷出
collide [kə'laid] v. (车等)碰撞 (with)；(意志等)冲突，抵触 (with)
energise ['enədʒaiz] =energize（美） vt. 供给 ... 能量，使精力充沛 vi. 释放出能量
Useful Expressions
take one’s breath away 屏息凝神
with regularity 经常地
be restricted to 局限于
lay eyes on 看到，看见
a hint of 一丁点儿
collide with (车等)碰撞；(意志等)冲突，抵触
as such 这样；因此
keep an eye out for 留心
Proper Names
Aurora Borealis 北极光
the Inuit 因纽特人；爱斯基摩人
Aristotle 亚里斯多德
Charles Hall 查尔斯 霍尔
Maori 毛利人；毛利语
Finland 芬兰
Lapland region 拉普兰地区
Arctic Circle 北极圈 (北纬66度33分以北区域)
Helsinki 赫尔辛基 (芬兰首都)
Notes
1.Aurora Borealis: 北极光--- "北端的光"
由太阳风和地球磁场及上层大气交互作用产生。与南极光(aurora australis)一起,统称为极光。aurora borealis 这个词是由一个法国的科学家Pierre Gassendi命名的。
2. Aurora: 古希腊曙光女神
　　古希腊女神奥罗拉(也叫厄俄斯)是曙光女神，她在将光明带往人间的时候，爱上了忧郁的特洛伊王子梯托诺斯，并将王子带回了奥林匹斯山。月亮女神阿尔忒弥斯帮助她将王子藏了起来，并告诉他去宙斯的神殿祈求王子得到长寿。奥罗拉向宙斯祈求了王子的长寿，却忘记了祈求他的永葆青春。于是王子迅速地老去，并被奥罗拉嫌弃，扔回了人间。但是奥罗拉为他生下了孩子，想把孩子留在奥林匹斯，可是宙斯不同意。趁奥罗拉不在，宙斯把孩子带回了人间，奥罗拉悲痛欲绝，却毫无办法。因为女神的悲伤，世界失去了光明。最后奥罗拉被宙斯劝说，继续为人间带来光明。
3. Borealis: 是指北部地区
Borealis与Australis相对, Australis是指南部地区。
起源:这个词是由希腊语Boreas而来,就是北风的意思。在希腊语中,各个方向的的风都有属于自己的名字：Notus南风；Zephyrus西风；Euro东风。

4. Finland：芬兰
芬兰位于欧洲北部，与瑞典挪威、俄罗斯接壤，有“千湖之国”之称。芬兰最早的居民为拉普人，故芬兰又称拉普兰。
5. Lapland region：拉普兰
拉普兰是芬兰最大、同时也是最北端的省份。拉普兰的旅游景点非常有特色，且野生动物资源丰富，因此吸引了全球各地的人们前来观光。拉普兰有着芬兰最富有盛名的国家公园，如圣诞村。此外，它还是观测北极光的最佳地点之一。到此一游堪称是旅游的最高境界，终极追求。
6. Helsinki:（芬兰首都）赫尔辛基 赫尔辛基不仅是芬兰首都，同时也是这个国家的最大城市。
Section B Aurora Borealis
The aurora is a widespread curtain-like coloured glow in the upper atmosphere. In the Arctic circle, the aurora appears as a ring-shaped glow, like a halo (晕圈), over the northern point of Scandinavia, the Siberian coast, Alaska, northern Canada, and the southern tip of Greenland.
This glow is caused by high-energy electrons colliding with oxygen atoms and nitrogen (氮)molecules. The basic process is the same as that of a neon sign (广告霓虹灯), which involves a vacuum (真空)and a high voltage (电压)electrical discharge (放电).
The electric power is generated by a combination of the solar wind, a hot ionized(电离)gas blowing out from the sun, and the Earth's magnetic field. Scientifically, the Aurora occurs when the Earth’s magnetic field collides with the solar wind coming from the Sun, causing a transfer of energy that creates the northern hemisphere to glow, specifically around the Poles. This produces more than 1,000 times the electrical power of the world's largest power plant.
The eruptions are loosely tied to the solar activity cycle, which lasts about 11 years. The largest terrestrial(地球上的) effects tend to happen when activity is at its maximum and in the years following maximums. However, large disturbances can happen at any part of the cycle.
In addition, the occurrence of auroras still depends on the latitude of the observer. The Aurora Lights form an oval band around the magnetic poles of the earth. At a distance about 2500 km from these poles, the probability for seeing auroras is almost 100 %.
The Northern Lights have several colourful variations (变差). The combination of yellows, pinks and greens are created by oxygen molecules that are found 60 miles above the earth’s atmosphere, whilst the blue and the combination of blue and purple is produced by nitrogen, and the rarest of all auroras, the red, is a product of high-altitude oxygen found 200 miles above Earth’s atmosphere.
One of the most wondrous (奇妙的) features of the aurora is its spectacular movement, as it swirls (弯曲盘旋) rapidly over the whole sky. This phenomenon is called the auroral substorm (磁层亚暴). The movement is caused by changes in both the electric and magnetic fields in the space around the earth. Changes in the fields are caused by solar eruptions called solar flares. We are still far from understanding the chain of processes that lead to the auroral substorm.
The prediction of the occurrence of auroras is difficult but we do have some success. There are two kinds of Northern Lights prediction: statistical and real-time ones. The former is based on a large amount of observations of Northern Lights at different latitudes during several years. From these statistics we can say what is the probability of the occurrence of Northern Lights during the course of year.
According to the statistics compiled(搜集) by the Finnish Meteorological (气象的) Institute, four nights out of five are illuminated (照亮) by Northern Lights in Northern Lapland, providing that the sky is free enough from clouds. On the coast of the Arctic Ocean in North Norway one can see Northern Lights almost every night. Even in South Finland, say Helsinki, one can see them but much more seldom; in Helsinki only one night out of 20.
The latter prediction is based on a space-weather monitoring system either by ground-based devices or satellites watching the space-weather conditions around the earth. When the monitoring devices, such as magnetometers (地磁仪) or particle detectors(检波器) in a satellite, show certain deviations (偏差) from the normal situation, one can expect that a space weather storm is approaching in a few hours.
The skill of real-time prediction is, unfortunately, rather low; we cannot make predictions for several days like forecasting normal weather. The reason for this shortcoming is that we do not fully understand the complicated processes, starting from the sun and ending in the near-space of the earth. Therefore, more space-research is needed for better forecasts. (662 words)

New Words
halo ['heiləu] n. (日月等的)晕，晕圈
nitrogen ['naitrədʒən] n. 氮
neon sign ['ni:,ɔn sain] n. 广告霓虹灯
vacuum ['vækjuəm] n. 真空
voltage ['vəultidʒ] n. 电压
discharge [dis'tʃɑ:dʒ] v. 放电
ionize ['aiənaiz] v. 使离子化 电离
terrestrial [ti'restriəl] a. 地球(上)的
variation [,vɛəri'eiʃən] n.【天文学】变差
wondrous ['wʌndrəs] a. 令人惊奇的，奇异的，奇妙的
swirl [swə:l] v. 打转; 弯曲盘旋
substorm [sʌb'stɔ:m] n. 【物理学】磁层亚暴〔地球磁层中的一种扰乱〕
compile [kəm'pail] v. 汇集，编辑; 搜集(资料)
meteorological [,mi:tiərə'lɔdʒikl] a. 气象的，气象学(上)的
illuminate [i'lju:mineit] v. 照亮，照明
magnetometer [,mægni'tɔmitə] n. 地磁仪
detector [di'tektə] n. 检波器，指示器
deviation [,di:vi'eiʃən] n. 偏向，偏差

Proper Names
Scandinavia 1. 斯堪的那维亚半岛2. 北欧
Siberian 西伯利亚的;来自西伯利亚的
Alaska 美国阿拉斯加州
Canada 加拿大
Greenland 格陵兰岛(北美东北的一大岛名,属丹麦)
Norway 挪威

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